The supernatant from two melanoma cell lines (PMEL and SMEL) with differential IL-1 expression (low versus high, respectively) was used in an in vitro endothelial cell permeability assay and results demonstrated that only IL-1 producing cell lines (SMEL and non-small-cell carcinoma, H2030) exhibited increased permeability that was inhibited by IL-1ra. The gene discussed is IL1B; the disease is non-small cell lung carcinoma.